Liquid crystal displays are commonly used as displays for compact electronic apparatuses, because they not only provide good quality images with little power but are also very thin. The liquid crystal in a liquid crystal display does not emit any light itself. The liquid crystal has to be lit by a light source so as to clearly and sharply display text and images. Thus, a backlight module is generally needed for a liquid crystal display.
Referring to FIG. 4, a typical backlight module 40 includes a light guide plate 41, a light source 43, a reflective film 45, and a bottom tray 47. The light guide plate 41, the light source 43, and the reflective film 45 are received in the bottom tray 47. The light guide plate 41 includes a light incident surface 412, a bottom surface 414 perpendicularly connected with the light incident surface 412, and a top surface 416 opposite to the bottom surface 414. The reflective film 45 is attached to the bottom surface 414 of the light guide plate 41. The light source 43 is located adjacent the light incident surface 412, and includes an illuminator 48, and a light source reflector 49 cooperating with the light incident surface 412 to generally surround the illuminator 48. The bottom tray 47 includes a planar bottom plate 472 adjacent the reflective film 45.
The light source reflector 49 has a symmetrically U-shaped profile. The light source reflector 49 includes a curved connection board 492, a top board 494, and a bottom board 496. The top board 494 and the bottom board 496 respectively extend from two opposite sides of the connection board 492, and are parallel to each other, thereby defining an opening (not labeled). The top board 494 and the bottom board 496 have a same width, and a distance therebetween is slightly greater than a total thickness of the light guide plate 41 and the reflective film 45. The top board 494 abuts an end portion (not labeled) of the top surface 416 of the light guide plate 41, and the bottom board 496 abuts an end portion (not labeled) of a bottom side (not labeled) of the reflective film 45.
In assembly of the backlight module 40, a step of aligning the light guide plate 41 attached with the reflective film 45 with the opening of the light source reflector 49 is needed, which makes the assembly of the backlight module 40 inconvenient and adds to the cost of manufacturing the backlight module 40.
What is needed, therefore, is a backlight module that can overcome the above-described deficiencies. What is also needed is a liquid crystal display employing such a backlight module.